The present invention relates generally, to the design and construction of a centrifugal separator apparatus for separating a composition into a substantially solid portion and a substantially fluid portion. More specifically, the present invention has one form wherein a pivoting plow motor assembly is moveable to engage a plow gear to drive a plow blade assembly. A bumper assembly allows the plow motor to reach a substantial torque before the plowing of the solid portion occurs. Although the present invention was developed for use in centrifugal separator systems, certain applications may be outside this field.
It is well known that in a centrifugal separator the separation of the solids and liquids in a contaminated fluid is accomplished by delivering the contaminated fluid to a high-speed rotating bowl. The high-speed rotation of the bowl creates centrifugal gravitational forces that cause the contaminated fluid to be displaced radially outward against the wall of the bowl. Since the bowl is rotating at a high rotational speed the solids tend to adhere to the bowl wall, while the substantially purified liquid exits through a discharge opening.
The centrifugal separator bowl must be periodically cleansed to remove the solids adhered to the bowl wall during the separation process. Failure to maintain the bowl in a dynamically balanced state and/or overloading with solid deposits can result in various problems. Such problems, for example, include: premature wear and failure of bushings, bearings, and seals; inefficient solid and liquid separation; overloading of the bowl motor drive; and, overloading the plow blade assembly drive motor. Prior designers of centrifugal separators have incorporated a mechanical plow blade within the bowl to remove accumulated deposits in an attempt to minimize problems associated with an over-load/unbalanced bowl.
One limitation associated with many prior centrifugal separator designs relates to the operation and configuration of the plow blade assembly. The plow blades extend generally radially from a center shaft, and therefore provide the same plow-action in either direction of rotation. The solids scraped from the bowl wall had a tendency to stick to the blades of the plow. Thus, it was often necessary to extend the clean cycle time in order to remove the solids from the blades. The extension of the clean cycle time is generally unacceptable because it increases the overall time required to process the liquid.
Even with a variety of earlier designs, there remains a need for an improved centrifugal separator apparatus. The present invention satisfies these needs, among others, in a novel and unobvious way.